FCC Supports National White Space Networking

Posted by
Sam Churchill
on
February 4th, 2013

The federal government wants to create super WiFi networks across the nation, says the Washington Post, so that consumers could use them to make calls or surf the Internet without paying a cellphone bill every month.

The CTIA, in its comments to the FCC, “urges the FCC to first place a high priority on making any reclaimed broadcast spectrum available for licensed use”. The commission should then develop a band plan “that maximizes the amount of spectrum made available without inhibiting or interfering with existing systems,” the CTIA said.

An equally intense campaign from Google, Microsoft and other tech giants, say additional unlicensed spectrum would spark an explosion of innovations and devices that would benefit most Americans, especially the poor.

The major wireless carriers own much more spectrum than what is being proposed for public use by the FCC, say advocates. Carrier-controlled spectrum allows more power and is available more universally. It can be used by many devices and is available exclusively to the carriers.

Wireless carriers are also planning to “usurp” the “free” Wi-Fi band by using roaming-enabled, Hotspot 2.0 technology. That could eliminate public hotspots that were once free, say advocates of more unlicensed spectrum.

The FCC band plan would maximize the amount of paired spectrum made available for the forward auction by offering equal amounts of uplink and downlink in paired 5×5 MHz blocks, with the paired uplink constituting the upper channels adjacent to the lower 700 MHz band to minimize interference problems.

The FCC proposes 6-MHz “guard” bands to prevent interference between mobile broadband services and broadcast TV services, spectrum that would be made available for unlicensed use.

Cognitive radio chips are used by the two major white space standards groups; IEEE 802.11af and IEEE 802.22. The maximum possible data rate per 6-MHz channel ranges from 18 to 22 Mbits/s. The 802.22 spec was designed for fixed rural use, operating on 6 MHz wide channels. In contrast, the 802.11af standard can aggregate channels into 5, 10, and 20 MHz bandwidths, and is designed for both mobile and fixed devices.

But “super wifi”, occupying unused broadcast television frequencies, seem unlikely to challange the big carriers. The channels are only 6 Mhz wide and limited to 100 milliwatts for mobile devices. Machine to machine communications might be a large user of the unlicensed spectrum since the 600 MHz spectrum could penetrate foliage and walls, but don’t need high speed connections.